Burglar-alarm.



No. 790,124. PATBNTBD MAY 16, 1905.V

J. HA-MMBRSMITH/ vBILIRGLAR ALARM.

APPLICATION vI'ILIID FEB. 18.1904.

i UNITED STATES Patented May 1e, 1905.

PATENT OEEICE.

JOSEPH HAMMERSMITH, OF CUMBERLAND, MARYLAND.

BURGLAR-ALARNI.

SPECIFICATION forming part of Letters Patent No. 790,124, dated May 16,1905.

Application filed February 18, 1904. Serial No. 194,146.

To @ZZ whom it mln/y concern,.-

Be it known that I, JOSEPH HAMMERSMITH, a citizen of the United States,residing at Oumberland, in the county of Allegany and State of Maryland,have invented certain new and useful Improvements in Burglar-Alarms, ofwhich the following is a specification.

My invention relates to improvements in burglar-alarms, and refersparticularly to that type of such alarms known as detonatingburglar-alarms. i

One object of my invention is the -provision of an alarm of thecharacter and for the purpose stated which upon the opening of the doorwill instantly fire a percussion-cap or blank cartridge and in additionwill hold the door and prevent it from being opened, and thus serve thetwofold Vpurpose of an alarm and a door-securer.

Another object of my invention is the provision of an alarm which can beapplied with ease and which will not mar or disiigure the door-frame andwhich will be inexpensive of production, simple and durable inconstruction, and thoroughly efficient and practical in operation.

With these objects in view my invention consists of' a burglar-alarmembodying novel features of construction and combinations of partssubstantially as disclosed herein.

Figure l represents an elevation of a portion of a door and casing withmy burglaralarm in position, the parts of the alarm being in theposition they occupy before an at-l tempt has been made to open thedoor. Fig. 2 represents a similar view with the door held secured andthe alarm having been operated or with the parts in the position theyoccupy when the door has been moved or partially opened. Fig. 3represents a detail sectional view showing how the burglar-armsacts tohold or secure the door. Figs. 4 and 5 represent enlarged elevations ofthe burglar-alarm, taken from opposite sides to fully show theconstruction and arrangement of the parts of the device; and Fig. 6represents an enlarged vertical central sectional View of the' alarmwith the parts in the position they assume when the device has beenoperated to detonate the cap or cartridge.

The burglar-alarm proper vconsists of thev base or casting O, which isformed with the ears or lugs D, provided with an alimng opening E, and,further, with the arm F, providedl with an opening G, in which is placeda percussion-'cap or cartridge H. Fitting within the openings E is theplunger J, which has at one end the firing-point K and upon lits upperend is formed with a curved arm L, adapted to travel on the curved .wayor guide M of the shell or casing N, and at the end of said guideway theshell is formed with a recess or kerf 0, in which the arm falls underthe action of the spring P, having one end connected to the base-plateat Q, and the other end connected at R to the plunger. The casing orshell is further provided with an extension or flap S, formed with apair of struck-up barbs or points T, which enter the casing or frame,and with openings to receive screws U for securing the alarm inposition. This being the construction, the consequent operation may bebriefly stated as follows: The parts are in position for operation, asshown in Fig. l, and immediately upon the. movement or partial openingof the door contact is made with the curved arm on the spring-plunger,and said arm is moved to the position'shown in Fig. 2, when the armfalls into the kerf or recess of the casing, allowing the spring toforce the plunger down and explode the cap, giving the alarm, and thecurved arm at this time is in the position shown in Fig. 3, where itengages the door and holds it from being opened further, Thus the deviceoperates to give the alarm upon an attempt to open the door and alsolocks or secures the door from further opening.

It isl evident that I provide a device which will perform its functionsof a burglar-alarm and door-securer in a thorough and efficient manner;also, that the device may be applied with ease and will not mark ordisiigure the door or casing and that it can be produced at such a priceas to commend. it as a useful, desirable, and practical article.

IOO

I claim- 1. An alarm consisting of a casing having substantially closedends, a rod in said casing extended through the upper and lower endsthereof, a curved arm at the upper end of the rod and a hammer formed atits lower end, said curved arm having its free end in the shape of ahook for engaging and securing the door when partially opened, a springwithin the casing surrounding the arm and connected to said arm andcasing, the casing provided with a lower extended portion having a seattherein for a percussion-cap below said hammer; the upper end of thecasing above its closed head formed with acurved inclined wallsurrounding the upper end of the rod casing extended through theupperand lower ends thereof, an integral curved arm at the upper end ofthe rod and a hammer formed at its lower end, said curved arm having itsfree end in the shape of a hook for engaging and securing the door whenpartially opened, a spring within the casing connected to said rod andcasing, an extension formed at the lower end of the casing provided witha seat for a percussion-cap in line with said hammer; the upper end ofthe casing above its closed end being provided with a curved inclinedwall and provided with a slot at its highest point, and means forfastening said casing` to the door-frame, substantially as described.

In testimony whereof] have signed my name to this specification inpresence of two witnesses.

JOSEPH H AM MERSM ITI-l.

Witnesses:

CHAs. E. M a'rz, FLOYD V. GILES.

